I used to keep my breeder mice in an open-topped aquarium up on top of a tall bookcase.
One day I came home to find that my cat had climbed the bookcase (must have done it ladder style - more than 6 feet high and no nearby furniture) and was sitting with a baffled look on her face, surrounded by absolutely still, frozen, mice. She hadn't touched a one - had seen them moving around, been interested enough to climb the bookcase, but once they froze she lost them completely.
Once I'd got her out, the mice all returned to their normal business - not noticeably permanently traumatised.
From which I learned three things:
1) You need a top on an enclosure no matter where it is
2) Cats are funny beings
3) Mice (and rats) have this amazing defense in the face of predators - stop moving!
So yes, I'd move the rats away from the feeding tank in future in the interests of kindness, but I wouldn't feel too guilty about the past - you had triggered a defense mechanism, not a mental breakdown.
By the way I think it is entirely a personal decision whether to feed in the main snake enclosure or to use feeding tubs - I happen to be a feeding tub person and not particularly interested in debating or defending that choice.
Similarly the choice to feed f/t or live - as long as you know the pros and cons of each and make wise decisions (such as never leaving a snake unattended with a live rodent) I don't see it's anyone else's business unless the OP asks for advice - and it wasn't really the point of this original post.
So there!